From a539f5d46c868cb1f37b92e62e040b400571aed4 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Wed, 6 Apr 2011 11:17:10 +0100 Subject: [PATCH] ARM: kprobes: Remove redundant condition checks from simulation routines Now we have the framework code handling conditionally executed instructions we can remove redundant checks in individual simulation routines. Signed-off-by: Jon Medhurst Signed-off-by: Nicolas Pitre --- arch/arm/kernel/kprobes-decode.c | 30 +++--------------------------- 1 file changed, 3 insertions(+), 27 deletions(-) diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index 2e84169..f52fac0c5 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -71,10 +71,6 @@ #define PSR_fs (PSR_f|PSR_s) #define KPROBE_RETURN_INSTRUCTION 0xe1a0f00e /* mov pc, lr */ -#define SET_R0_TRUE_INSTRUCTION 0xe3a00001 /* mov r0, #1 */ - -#define truecc_insn(insn) (((insn) & 0xf0000000) | \ - (SET_R0_TRUE_INSTRUCTION & 0x0fffffff)) typedef long (insn_0arg_fn_t)(void); typedef long (insn_1arg_fn_t)(long); @@ -419,14 +415,10 @@ insnslot_llret_4arg_rwflags(long r0, long r1, long r2, long r3, long *cpsr, static void __kprobes simulate_bbl(struct kprobe *p, struct pt_regs *regs) { - insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; long iaddr = (long)p->addr; int disp = branch_displacement(insn); - if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) - return; - if (insn & (1 << 24)) regs->ARM_lr = iaddr + 4; @@ -446,14 +438,10 @@ static void __kprobes simulate_blx1(struct kprobe *p, struct pt_regs *regs) static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs) { - insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; int rm = insn & 0xf; long rmv = regs->uregs[rm]; - if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) - return; - if (insn & (1 << 5)) regs->ARM_lr = (long)p->addr + 4; @@ -465,7 +453,6 @@ static void __kprobes simulate_blx2bx(struct kprobe *p, struct pt_regs *regs) static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs) { - insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; kprobe_opcode_t insn = p->opcode; int rn = (insn >> 16) & 0xf; int lbit = insn & (1 << 20); @@ -476,9 +463,6 @@ static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs) int reg_bit_vector; int reg_count; - if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) - return; - reg_count = 0; reg_bit_vector = insn & 0xffff; while (reg_bit_vector) { @@ -510,11 +494,6 @@ static void __kprobes simulate_ldm1stm1(struct kprobe *p, struct pt_regs *regs) static void __kprobes simulate_stm1_pc(struct kprobe *p, struct pt_regs *regs) { - insn_1arg_fn_t *i_fn = (insn_1arg_fn_t *)&p->ainsn.insn[0]; - - if (!insnslot_1arg_rflags(0, regs->ARM_cpsr, i_fn)) - return; - regs->ARM_pc = (long)p->addr + str_pc_offset; simulate_ldm1stm1(p, regs); regs->ARM_pc = (long)p->addr + 4; @@ -1056,9 +1035,8 @@ space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) /* BLX(2) : cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */ /* BX : cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */ if ((insn & 0x0ff000d0) == 0x01200010) { - asi->insn[0] = truecc_insn(insn); asi->insn_handler = simulate_blx2bx; - return INSN_GOOD; + return INSN_GOOD_NO_SLOT; } /* CLZ : cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */ @@ -1333,10 +1311,9 @@ space_cccc_100x(kprobe_opcode_t insn, struct arch_specific_insn *asi) /* LDM(1) : cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */ /* STM(1) : cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */ - asi->insn[0] = truecc_insn(insn); asi->insn_handler = ((insn & 0x108000) == 0x008000) ? /* STM & R15 */ simulate_stm1_pc : simulate_ldm1stm1; - return INSN_GOOD; + return INSN_GOOD_NO_SLOT; } static enum kprobe_insn __kprobes @@ -1344,9 +1321,8 @@ space_cccc_101x(kprobe_opcode_t insn, struct arch_specific_insn *asi) { /* B : cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */ /* BL : cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */ - asi->insn[0] = truecc_insn(insn); asi->insn_handler = simulate_bbl; - return INSN_GOOD; + return INSN_GOOD_NO_SLOT; } static enum kprobe_insn __kprobes -- 2.7.4